NAME

SYNOPSIS

xscreensaver-demo [-display host:display.screen] [-prefs] [--debug]

DESCRIPTION

The xscreensaver-demo program is a graphical front-end for setting the
parameters used by the background xscreensaver(1) daemon. It is
essentially two things: a tool for editing the ~/.xscreensaver file;
and a tool for demoing the various graphics hacks that the xscreensaver
daemon will launch.
The main window consists of a menu bar and two tabbed pages. The first
page is for editing the list of demos, and the second is for editing
various other parameters of the screensaver.

MENUCOMMANDS

All of these commands are on either the File or Help menus:
BlankScreenNow
Activates the background xscreensaver daemon, which will then run a
demo at random. This is the same as running xscreensaver-command(1) with the -activate option.
LockScreenNow
Just like BlankScreenNow, except the screen will be locked as
well (even if it is not configured to lock all the time.) This is
the same as running xscreensaver-command(1) with the -lock option.
KillDaemon
If the xscreensaver daemon is running on this screen, kill it.
This is the same as running xscreensaver-command(1) with the -exit
option.
RestartDaemon
If the xscreensaver daemon is running on this screen, kill it.
Then launch it again. This is the same as doing ‘‘xscreensaver-command-exit’’ followed by ‘‘xscreensaver’’.
Note that it is not the same as doing ‘‘xscreensaver-command-restart’’.
Exit
Exits the xscreensaver-demo program (this program) without
affecting the background xscreensaver daemon, if any.
About...
Displays the version number of this program, xscreensaver-demo.
Documentation...
Opens up a web browser looking at the XScreenSaver web page, where
you can find online copies of the xscreensaver(1),
xscreensaver-demo(1), and xscreensaver-command(1) manuals.

DISPLAYMODESTAB

This page contains a list of the names of the various display modes, a
preview area, and some fields that let you configure screen saver
behavior.
Mode
This option menu controls the behavior of the screen saver. The
options are:
DisableScreenSaver
Don’t ever blank the screen, and don’t ever allow the
monitor to power down.
BlankScreenOnly
When blanking the screen, just go black: don’t run any
graphics hacks.
OnlyOneScreenSaver
When blanking the screen, only ever use one particular
display mode (the one selected in the list.)
RandomScreenSaver
When blanking the screen, select a random display mode
from among those that are enabled and applicable. This
is the default.
RandomSameSaver
This option only appears if you have multiple monitors.
This is just like RandomScreenSaver, except that the
same randomly-chosen display mode will be run on all
monitors, instead of a different one being run on each.
DemoList
Double-clicking in the list on the left will let you try out the
indicated demo. The screen will go black, and the program will run
in full-screen mode, just as it would if the xscreensaver daemon
had launched it. Clicking the mouse again will stop the demo and
un-blank the screen, making the dialog box visible again.
Single-clicking in the list will run it in the small preview pane
on the right. (But beware: many of the display modes behave
somewhat differently when running in full-screen mode, so the
scaled-down view might not give an accurate impression.)
When Mode is set to RandomScreenSaver, each name in the list has
a checkbox next to it: this controls whether this display mode is
enabled. If it is unchecked, then that mode will not be chosen.
(Though you can still run it explicitly by double-clicking on its
name.)
ArrowButtons
Beneath the list are a pair of up and down arrows. Clicking on the
down arrow will select the next item in the list, and then run it
in full-screen mode, just as if you had double-clicked on it. The
up arrow goes the other way. This is just a shortcut for trying
out all of the display modes in turn.
BlankAfter
After the user has been idle this long, the xscreensaver daemon
will blank the screen.
CycleAfter
After the screensaver has been running for this long, the currently
running graphics demo will be killed, and a new one started. If
this is 0, then the graphics demo will never be changed: only one
demo will run until the screensaver is deactivated by user
activity.
LockScreen
When this is checked, the screen will be locked when it activates.
LockScreenAfter
This controls the length of the ‘‘grace period’’ between when the
screensaver activates, and when the screen becomes locked. For
example, if this is 5 minutes, and BlankAfter is 10 minutes, then
after 10 minutes, the screen would blank. If there was user
activity at 12 minutes, no password would be required to un-blank
the screen. But, if there was user activity at 15 minutes or later
(that is, LockScreenAfter minutes after activation) then a
password would be required. The default is 0, meaning that if
locking is enabled, then a password will be required as soon as the
screen blanks.
Preview
This button, below the small preview window, runs the demo in full-
screen mode so that you can try it out. This is the same thing
that happens when you double-click an element in the list. Click
the mouse to dismiss the full-screen preview.
Settings
This button will pop up a dialog where you can configure settings
specific to the display mode selected in the list.

ADVANCEDTAB

This tab lets you change various settings used by the xscreensaver
daemon itself, rather than its sub-programs.
GrabDesktopImages
Some of the graphics hacks manipulate images. If this option is
selected, then they are allowed to manipulate the desktop image,
that is, a display mode might draw a picture of your desktop
melting, or being distorted in some way. The security-paranoid
might want to disable this option, because if it is set, it means
that the windows on your desktop will occasionally be visible while
your screen is locked. Others will not be able to do anything, but
they may be able to see whatever you left on your screen.
GrabVideoFrames
If your system has a video capture card, selecting this option will
allow the image-manipulating modes to capture a frame of video to
operate on.
ChooseRandomImage
If this option is set, then the image-manipulating modes will
select a random image file from disk, from the directory you
specify in the text entry field. That directory will be
recursively searched for files, and it is assumed that all the
files under that directory are images.
If more than one of these options are selected, then one will be
chosen at random. If none of them are selected, then an image of
video colorbars will be used instead.
(All three of these options work by invoking the
xscreensaver-getimage(1) program, which is what actually does the
work.)
TextManipulation
Some of the display modes display and manipulate text. The
following options control how that text is generated. (These
parameters control the behavior of the xscreensaver-text(1)
program, which is what actually does the work.)
HostNameandTime
If this checkbox is selected, then the text used by the screen
savers will be the local host name, date, time, and system load.
Text
If this checkbox is selected, then the literal text typed in the
field to its right will be used. If it contains % escape
sequences, they will be expanded as per strftime(2).
TextFile
If this checkbox is selected, then the contents of the
corresponding file will be displayed.
Program
If this checkbox is selected, then the given program will be run,
and its output will be displayed.
URL If this checkbox is selected, then the given HTTP URL will be
downloaded and displayed repeatedly. If the document contains
HTML, RSS, or Atom, it will be converted to plain-text first.
Note: this re-downloads the document every time the screen saver
runs out of text! It might be considered abusive for you to point
this at a web server that you do not control, as it will probably
be hitting that server multiple times a minute.
PowerManagementEnabled
Whether the monitor should be powered down after a period of
inactivity.
If this option is grayed out, it means your X server does not
support the XDPMS extension, and so control over the monitor’s
power state is not available.
If you’re using a laptop, don’t be surprised if this has no effect:
many laptops have monitor power-saving behavior built in at a very
low level that is invisible to Unix and X. On such systems, you
can typically only adjust the power-saving delays by changing
settings in the BIOS in some hardware-specific way.
StandbyAfter
If PowerManagementEnabled is selected, the monitor will go black
after this much idle time. (Graphics demos will stop running,
also.)
SuspendAfter
If PowerManagementEnabled is selected, the monitor will go into
power-saving mode after this much idle time. This duration should
be greater than or equal to Standby.
OffAfter
If PowerManagementEnabled is selected, the monitor will fully
power down after this much idle time. This duration should be
greater than or equal to Suspend.
FadeToBlackWhenBlanking
If selected, then when the screensaver activates, the current
contents of the screen will fade to black instead of simply winking
out. (Note: this doesn’t work with all X servers.) A fade will
also be done when switching graphics hacks (when the CycleAfter
expires.)
UnfadeFromBlackWhenUnblanking
The complement to FadeColormap: if selected, then when the
screensaver deactivates, the original contents of the screen will
fade in from black instead of appearing immediately. This is only
done if FadeColormap is also selected.
FadeDuration
When fading or unfading are selected, this controls how long the
fade will take.
InstallColormap
On 8-bit screens, whether to install a private colormap while the
screensaver is active, so that the graphics hacks can get as many
colors as possible. This does nothing if you are running in 16-bit
or better.
There are more settings than these available, but these are the most
commonly used ones; see the manual for xscreensaver(1) for other
parameters that can be set by editing the ~/.xscreensaver file, or the
X resource database.

SETTINGSDIALOG

When you click on the Settings button on the DisplayModes tab, a
configuration dialog will pop up that lets you customize settings of
the selected display mode. Each display mode has its own custom
configuration controls on the left side.
On the right side is a paragraph or two describing the display mode.
Below that is a Documentation button that will display the display
mode’s manual page, if it has one, in a new window (since each of the
display modes is actually a separate program, they each may have their
own manual.)
The Advanced button reconfigures the dialog box so that you can edit
the display mode’s command line directly, instead of using the
graphical controls. It also lets you configure the X visual type that
this mode will require. If you specify one (other than Any) then the
program will only be run on that kind of visual. For example, you can
specify that a particular program should only be run if color is
available, and another should only be run in monochrome. See the
discussion of the programs parameter in the Configuration section of
the xscreensaver(1) manual. (OpenGL programs should always have their
visual set to "GL".)

COMMAND-LINEOPTIONS

xscreensaver-demo accepts the following command line options.
-displayhost:display.screen
The X display to use. The xscreensaver-demo program will open
its window on that display, and also control the xscreensaver
daemon that is managing that same display.
-prefs Start up with the Advanced tab selected by default instead of
the DisplayModes tab.
-debug Causes lots of diagnostics to be printed on stderr.
It is important that the xscreensaver and xscreensaver-demo processes
be running on the same machine, or at least, on two machines that share
a file system. When xscreensaver-demo writes a new version of the
~/.xscreensaver file, it’s important that the xscreensaver see that
same file. If the two processes are seeing different ~/.xscreensaver
files, things will malfunction.

ENVIRONMENT

DISPLAY to get the default host and display number.
PATH to find the sub-programs to run. However, note that the sub-
programs are actually launched by the xscreensaver daemon, not
by xscreensaver-demo itself. So, what matters is what $PATH
the xscreensaver program sees.
HOME for the directory in which to read and write the .xscreensaver
file.
XENVIRONMENT
to get the name of a resource file that overrides the global
resources stored in the RESOURCE_MANAGER property.
HTTP_PROXY or http_proxy
to get the default HTTP proxy host and port.